Pat Valdata asks: 

> Could they have been Tundra Swans this late?

According to the Yellow Book, Tundra Swans are here in Maryland
through mid- to late-May.  In some, but not all, years, Tundras have
been present right through the summer before their return in numbers
in late October.  They are also seen every year in all 23 counties.

Best,
Norm

================================
Norm Saunders
Colesville & West Ocean City, MD